• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.112-118
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• 2018

In order to meet the strict emission regulations for internal combustion engines based on fossil fuel, the proportion of after-treatments for vehicles and vessels is gradually increasing. Diesel engines have high power, good fuel economy, and lower $CO_2$ emissions, and their market shares are increasing in commercial vehicles and passenger cars. However, NOx is generated in the localized high-temperature combustion regions, and particulate matter is formed in the zones of diffusion combustion. LNT and urea-SCR catalysts have been developed for after-treatment of the exhaust gas to reduce NOx in diesel vehicles. This study aims to improve the NOx reduction performance of Cu SCR catalyst, which is widely used in light, medium, and heavy-duty diesel engines. The de-NOx performance of $5Cu-2ZrO_2$/93Zeolyst(Si/Al=13.7) SCR catalyst was about 5-50% higher than that of $5Cu-2ZrO_2$/93Zeolite(Si/Al=2.9) at catalyst temperatures of $300^{\circ}C$ or higher. The zeolite had lower metal dispersion than zeolyst, and the reaction rate of the catalyst decreased as the average particle size increased. The $10Cu-2ZrO_2$/88Zeolyst catalyst loaded with 10wt% Cu had the highest NOx conversion rate of 40% at $200^{\circ}C$ and about 65% at $350^{\circ}C$. The ion exchange rate of Cu ions increased with that of Al, the crystalline compound of zeolite, and the de-NOx performance was improved by 20-40% compared to other catalysts.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.200-207
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• 2019

Cement is one of the most commonly used materials in the construction and civil engineering industry. However, emissions of carbon dioxide generated during the production of cement have been linked to climate change and environment pollutants. In order to replace cement, many studies have been actively performed research to utilizing Blast Furnace Slag(BFS), which is a byproduct of the steel industry. This study aims to investigate the physiochemical properties of the BFS powder based grout to determine whether it can be used as an environment-friendly grout material. As a fine powder, BSF can be used instead of cement grout due to its potential hydraulic property. BSF has also been known for its ability to strengthen materials long-term and to densify the internal structure of concrete. In order to investigate the physicochemical properties of the BFS powder based grout as a grout material, in this study assessment tests were performed through a gel-time measurement, uniaxial compressive strength, and chemical resistance tests, and heavy-metal leaching test. Characteristics and advantages of the slag were studied by comparing slag and cement in various methods.

• Journal of the Korean earth science society
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• v.26 no.6
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• pp.573-583
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• 2005

[ $PM_{10}\;and\;PM_{2.5}$ ] aerosols were collected at Busan from March, 2004 to December, 2004, and the concentrations of some metal elements were chemically analyzed to study their characteristics. The mean concentration of $PM_{10}$ was $58.2{\mu}g/m^3$ with a range of 8.3 to $161.1{\mu}g/m^3$. The mean concentration of $PM_{2.5}$ was $29.3{\mu}g/m^3$ with a range of 2.8 to $65.3\mu}g/m^3$. The mean mass concentrations of Asian dust and non Asian dust in $PM_{10}$ were $121.5\mu}g/m^3$ and $56.0{\mu}g/,^3$ respectively. The mean values of crustal enrichment factors for six elements (Cd, Cr, Cu, Ni, Pb and Zn) were all higher than 10, possibly suggesting the influence of anthropogenic sources. The crustal enrichment factors of some heavy metal elements in non-Asian dust (NAD) were higher than those in Asian dust (AD), possibly due to anthropogenic emissions transported from industries around this area by westerly wind. The soil contribution ratios for $PM_{10}$ and $PM_{2.5}$ were $15.2\%$ and $17.5\%$ on the whole. and those of AD/NAD for $PM_{10}$ and $PM_{2.5}$ were 1.9 and 2.1, respectively.